The O.C. S02 E19 The Rager

"It's nothing like where you live. And nothing like you imagine."

It's Trey's 21st birthday and Marissa, anxious to help Trey and Ryan forge a relationship, throws a birthday party for Trey at the Cooper-Nichol mansion that turns out to be a rager. Seth is left in hot water by both Summer and Zach, but why? Sandy wants to continue his friendship with Carter, leaving a confused Kirsten. Meanwhile, Julie shares some memories with an "old" friend and in the process learns a few things and gains a few ideas.